Now that retail cannabis is legal in Washington, there’s a lot of speculation about its potential benefits and harms. Whether it’s marijuana, edibles, CBD products, or any other form, the choice to use cannabis during pregnancy and breastfeeding is nuanced—people have different circumstances and situations that may contribute to using cannabis. However, it is not recommended to use during this time – not even in the form of CBD lotions or edibles. There are established risks from cannabis use that can negatively impact people and their children.

We asked Dr. Joel Carey, M.D., to tell us about these risks. Dr. Carey is a family medicine physician who is earning a Master of Public Health degree at the University of Washington. He is currently working on a project at Public Health – Seattle & King County about informing people of the risks of cannabis use while pregnant or breastfeeding. Here are his key messages:

• Cannabis use while pregnant or breastfeeding is a challenging topic. Research shows potential negative impacts, but there’s still a lot to learn about the exact effects on pregnant people and their children. Adding to the confusion are resources that recommend some forms of cannabis to manage pregnancy discomforts, stress, and pain. Plus, since retail and medical use is legal for adults in Washington, some people believe that cannabis isn’t harmful.

All of these factors make it difficult for people to know what is and isn’t recommended about cannabis use while they are pregnant or breastfeeding. So, it’s important to talk about what research shows so far about how cannabis can affect them and their children.

• Cannabis use during pregnancy can have negative effects. The THC in cannabis causes mind-altering reactions (aka a “high”), which can affect cognition and judgment. For people who are pregnant, this altered judgement could affect their ability to protect their babies—for example, cannabis use impairs safe driving skills and doubles a person’s risk of a car crash.

There is also evidence that using cannabis during pregnancy can harm fetal brain development and negatively affect kids later in life, including problems with their attention, memory, problem-solving skills, and behavior.

There are safer alternatives to using cannabis to manage morning sickness, nausea, stress, or pain during pregnancy. Healthcare providers can help people learn about different options.

• Research on breastfeeding is less extensive, but is still concerning. Research shows that chemicals in cannabis (like THC, CBD, and others) can be passed to babies through breast milk, which may negatively affect their development.

Plus, these chemicals can stay in breast milk for hours to several days—meaning babies are exposed for extended periods of time, and people are unable to know when the chemicals are gone from their breast milk.

• Parents and their children may experience additional negative social consequences. A healthcare provider may be mandated to report to the Department of Social and Health Services if they believe a parent’s substance use is causing child abuse or neglect.

• Research on the health impacts of cannabis is still limited, due to federal regulations. This means there is not as much evidence as we would like for either the safety or the harms of cannabis. Advocates for cannabis may make claims that are contrary to the risks we describe above. When it comes to pregnancy and children, it makes sense to use a precautionary approach.

There are several helpful resources to learn more about this topic:

The Washington Department of Health developed this handy info sheet on “5 Things to Know about marijuana use while pregnant or breastfeeding.” Translated versions are available here – scroll to the bottom of the page.

The Centers for Disease Control and Prevention produced this info sheet on “What you need to know about marijuana use and pregnancy.”